Motor-vehicle seat belt with integrated sensors

ABSTRACT

A safety belt has an inner face turned toward the body of a user and an outer face turned away from the user. A plurality of sensor are mounted on the outer face, and the inner face is devoid of sensors. A selector connected to the sensors determines which sensor is best positioned for signal quality and for using the signal therefrom.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the US national phase of PCT applicationPCT/EP2004/004378, filed 26 Apr. 2004, published 23 Dec. 2004 asWO2004/110829, and claiming the priority of German patent application10327753.6 itself filed 18 Jun. 2003, whose entire disclosures areherewith incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a sensor arrangement for attaching to a belt,in particular to a motor vehicle safety belt.

BACKGROUND OF THE INVENTION

With such sensor arrangements know from the prior art the sensors arearranged on the safety belt or are attached thereto, in that for examplefittings penetrating the safety belt or the like are provided. Common toall known fittings or attachments of the sensors on the safety belt isthat on the one hand the mechanical properties of the belt are impaired,whereby furthermore the support properties of the safety belt arechanged negatively insofar as the smooth structure of the inner face ofthe belt facing the occupants of the vehicle is disturbed by elements ofthe fittings or attachments projecting on the inner face of the safetybelt. This smooth structure of the inner face of the belt is however ofmajor significance to ensure the necessary easy-running gliding of thesafety belt over the deflection elements of the safety belt arrangementsand the body of the vehicle occupants. The result of any impairment tothese glide properties of the safety belt can be that the safety belt isno longer tightened optimally on the body of the vehicle occupants bythe retractors of the safety belt arrangement following movements of theoccupants of the vehicle.

In the event of a possible accident or the like the safety belt wouldthus deploy its protective function inadequately only, if at all.

OBJECT OF THE INVENTION

The object of the invention is to provide a sensor arrangement forapplying to a belt, in particular on a safety belt of a motor vehicle,which results in no or little impairing of the glide properties on theinner face of same essential for the protective function of the safetybelt.

SUMMARY OF THE INVENTION

This object is attained according to the present invention by at leastone, preferably each sensor of the sensor arrangement being arranged onthe outer face of the safety belt facing away from the body of thevehicle occupants, whereby the inner face of the safety belt facing thebody of the vehicle occupants remains free and unchanged.

Such applying or fixing of the sensors of the sensor arrangement on thebelt can be achieved if at least one sensor is taken up on a fitting orin a housing, which can be fastened on the outer face of the safetybelt.

The housing can be made advantageously from plastic.

The housing can be attached to the outer face of the safety belt bywelding with the material forming the outer face of the safety belt orby adhesion on the outer face of the safety belt.

It is also possible to sew the housing of at least one sensor on theouter face of the safety belt.

To prevent the safety belt from being partly weakened in those areaswhere the sensors of the sensor arrangement are provided, it isappropriate to reinforce the safety belt in these areas by weaving inadditional threads.

Alternatively, the belt can be reinforced in the areas with the sensorsof the sensor arrangement of the safety belt by adding in threads inthese areas with better mechanical properties, e.g. increased breakingload and/or elasticity, for physically forming the safety belt.

The sensors of the sensor arrangement can be designed e.g. asmicrophones. It is then possible, without the interference of handgrips, which might hinder proper control of the vehicle, to comfortablymake a selection.

Alternatively or additionally, sensors designed as heart frequency, bodytemperature meters or the like can be provided. In the event of a signalfrom a heart frequency meter, which whether the vehicle driver iscompetent to drive, operation of the vehicle can be taken over forexample such that as far as possible no or minimal damage will result.

The sensors of the sensor arrangement are appropriately connected toconductors integrated in the safety belt, into which or from which therequired operating energy of the sensor arrangement and signals of thesensors can be inductively coupled or uncoupled. The sensors of thesensor arrangement can be attached in different topologies. This dependson the structural type of the sensors. Sensors, which deliver anadequate signal value, are contacted individually or with a commonreference conductor. Sensors with low signal value frequently require aseparate voltage supply. Integrated sensors can be connected together toa common bus.

The operating power and the signals can advantageously be coupled oruncoupled in the region of one of two retractors or a belt lock of thesafety belt arrangement.

With respect to their breaking and expansion properties, conductorswoven into the safety belt have particularly advantageous properties, ifthe conductors are woven right in as the original filament of the safetybelt. The angle and spacing of the conductors during weaving thendetermine the expansion behavior. In addition, the conductors in thisadvantageous embodiment of the invention are not visible from outside.

The connection between the sensors on the one hand and the conductorsintegrated into the safety belt on the other hand can advantageously beeffected by means of flexiconductors or conductive elastomers.

In order to determine the sensor of the sensor arrangement bestpositioned for the respective purpose, it is advantageous if a selectiondevice is provided by means of which the sensor of the sensorarrangement best positioned for the signal quality can be determined,whereby the signal of this sensor can then be selected for forwarding.

To further improve the output signal the selection device should selectthe two sensors of the sensor arrangement best positioned for signalquality, e.g. the first sensor arranged above and the first sensorarranged below the signal source, and should form the output signal ofthe sensor arrangement from the signals of both these sensors. Thesignals of the sensors can be processed by amplifying and standardizingthe signals, but also with linearizing and filtering of the signals. Thebest positioned sensor or the best-positioned sensor group can beselected by signal-evaluation without consideration for the belt lengthor the seated position by means of the selection device.

The output signal of the selected sensor or selected sensor groupincluding the signals of the other sensors of the sensor arrangement canbe processed preferably according to any mathematical method, with thepossibility for example of filtering out wind noise, e.g. in aconvertible, from a microphone signal.

The selection device can operate in view of the output signals from aseated position sensor and/or a sensor for the weight of occupants ofthe vehicle and/or a safety belt length of stretch sensor, andindependently make the selection of the best-positioned sensors.

BRIEF DESCRIPTION OF THE DRAWING

The invention will now be explained in greater detail hereinbelow bymeans of an embodiment with reference to the diagram, in which:

FIG. 1 is a basic illustration of a safety belt fitted with a sensorarrangement according to the present invention, and

FIG. 2 illustrates section A-A in FIG. 1.

SPECIFIC DESCRIPTION

A safety belt 1 shown in a basic illustration in FIG. 1 is subdividedinto a shoulder belt part 2 running obliquely upward and a lap belt part3 running approximately horizontally.

A sensor arrangement is provided on the front side of the safety belt 1visible in FIG. 1 and turned away from the body of a person protected bythe safety belt 1, to which a plurality of sensors 4 belongs. In theillustrated embodiment the sensors 4 of the sensor arrangement arearranged at approximately the same spacing in a longitudinal directionboth of the shoulder belt part 2 and also of the lap belt part 3.

As already explained, the sensors 4 sit on the outer face 5 of thesafety belt 1 facing away from the vehicle occupants.

The inner face 6 of the safety belt 1 is not impaired by the sensors 4of the sensor arrangement and is fully undisturbed. The run of thesafety belt 1 in deflection elements and the like is thus not hinderedby the sensors 4 of the sensor arrangement.

In the illustrated embodiment each sensor 4 of the sensor arrangementhas a housing 7 in which it is received and by means of which it ismounted on the outer face 5 of the safety belt 1. Depending on thephysical form of the sensor 4 it is also possible to arrange the latternot by means of a housing 7 but by means of another kind of fitting onthe outer face 5 of the safety belt 1.

As best evident from FIG. 2, the housing 7 containing the sensor 4 isconnected by means of a connection 8 solidly to the material forming theouter face 5 of the safety belt 1. The connection 8 can be a weld joint,an adhesive joint and also a seam or the like.

The safety belt 1 can be strengthened by means of woven-in threads atthose points, at which the sensors 4 of the sensor arrangement areprovided, to balance out any possible weaknesses of the safety belt 1,occurring due to the mounting of the sensors 4.

The sensors 4 illustrated in FIG. 1 or 2 can be for example microphones,which it is possible for the occupant of the vehicle to use withouthaving to manipulate any distracting hand grips impairing hisconcentration on controlling the vehicle. Of course, the sensorarrangement formed by the sensors 4 can be provided on every safety beltinside the vehicle.

Alternatively or in addition to this, sensors 4 designed as heartfrequency and body temperature sensors or the like can be provided.

In the embodiment illustrated in the figures conductors 9 are integratedin the safety belt 1 for power supply and for signal connection of thesensors 4. The required operating energy can be fed to the sensors 4 bymeans of these conductors 9, whereby the signal output from the sensors4 can take place by means of the conductors 9 also.

Both coupling of the operating power required for operating the sensors4 and also uncoupling the signals from the sensors 4 can be carried outinductively, whereby one of two retractors of the safety belt 1 canserve as coupling or uncoupling point.

The conductors 9 integrated in the safety belt 1 can be spun about webfilaments of the safety belt 1.

The connection between the conductors 9 on the one hand and the sensors4 on the other hand can be realized by means of flexiconductors,conductive elastomers and the like.

The sensor arrangement formed by the sensors 4 includes a selectiondevice not shown in FIGS. 1 and 2, which receives signals from allsensors 4 of the sensor arrangement. The signal quality of theindividual sensors 4 can be established in the selection device notshown in the figures. It is possible, by means of the selection device,to select a particular sensor or two sensors 4 whose signal quality isbest. As long as both sensors 4 with the best signal quality areselected, their signals can be combined into one output signal.

Also, it is possible to refine this output signal further, in that thesignals of the sensors 4 not selected for combining the output signalare considered and employed for processing the output signal.

One seated position sensor and one sensor for the weight of theoccupants of the vehicle can be connected to the selection device. Itsoutput signals can be used in selection of the sensors 4 of the sensorarrangement best positioned for signal quality, whereby the outputsignal of a safety belt length of stretch sensor can be considered forthis selection also.

1. In a motor-vehicle safety belt having an inner face turned toward thebody of a user and an outer face turned away from the user, a sensorarrangement comprising: at least one sensor on the outer face to detectone or more parameters of the user, the inner face being devoid of anysensor; the belt being reinforced at least adjacent the at least onesensor with filaments of greater strength than filaments otherwiseforming the belt.
 2. The sensor arrangement as claimed in claim 1wherein the sensor is contained a fitting or housing fastened to theouter face of the safety belt.
 3. The sensor arrangement as claimed inclaim 2 wherein the housing of is made of plastic.
 4. The sensorarrangement as claimed in claim 2 wherein the housing is welded tomaterial forming the outer face of the safety belt.
 5. The sensorarrangement as claimed in claim 2 wherein the housing is adhered tomaterial forming the outer face of the safety belt.
 6. The sensorarrangement as claimed in claim 2 wherein the housing is sewn to theouter face (5) of the safety belt.
 7. In a motor-vehicle safety belthaving an inner face turned toward the body of a user and an outer faceturned away from the user, a sensor arrangement comprising: at least onesensor on the outer face to detect one or more parameters of the user,the inner face being devoid of any sensor; and conductors integratedinto the belt and connected to the at least one sensor and detectioncircuitry.
 8. The sensor arrangement as claimed in claim 7 wherein thesafety belt is provided in the region of the sensor with beltreinforcing.
 9. The sensor arrangement as claimed in claim 8 wherein thebelt reinforcing is filaments additionally woven into the safety belt.10. The sensor arrangement as claimed in claim 8 wherein the beltreinforcing is filaments with better mechanical properties.
 11. Thesensor arrangement as claimed in claim 7 wherein the operating energyand signal of the at least one sensor can be coupled or uncoupled in theregion of one of two retractors or a belt lock of the safety belt. 12.The sensor arrangement as claimed in claim 7 wherein the conductorsintegrated in the safety belt are woven with filaments of the safetybelt.
 13. In a motor-vehicle safety belt having an inner face turnedtoward the body of a user and an outer face turned away from the user, asensor arrangement comprising: a plurality of sensors on the outer faceto detect one or more parameters of the user, the inner face beingdevoid of any sensor; and selector means for determining which sensor isbest positioned for signal quality and for using the signal therefrom.14. The sensor arrangement as claimed in claim 13 wherein there are aplurality of the sensors that are each arranged on the outer face of thesafety belt facing away from the body of the vehicle occupants, theinner face of the safety belt facing the body of the vehicle occupantsbeing free and unchanged.
 15. The sensor arrangement as claimed in claim13 wherein the sensors are microphones.
 16. The sensor arrangement asclaimed in claim 13 wherein the sensors detect heart frequency or bodytemperature.
 17. The sensor arrangement as claimed in claim 13 whereinthe sensors are connected by means of flexiconductors to the conductorsintegrated in the safety belt.
 18. The sensor arrangement as claimed inclaim 17 wherein the sensors are connected by means of conductiveelastomers to the conductors integrated in the safety belt.
 19. Thesensor arrangement as claimed in claim 13 wherein by means of theselector means the two sensors of the sensor arrangement best positionedfor signal quality can be determined and the signals of both thesesensors can be combined into one output signal.
 20. The sensorarrangement as claimed in claim 13 wherein an output signal of theselected sensor or an output signal combined from the signals of two ormore selected sensors along with the signals of the other sensors of thesensor arrangement can be processed preferably according to anymathematical method.
 21. The sensor arrangement as claimed in claim 13wherein the selector means is connected to a seated position sensor or asensor for weight of the occupants of the vehicle, whereby the outputsignals of this or respectively of these sensors can be viewed togetherwith an output signal of a safety belt length of stretch sensor inselection of the best-positioned sensors of the sensor arrangement.